The present invention relates to a bipolar type semiconductor device (quantum base transistor: QBT) having an operating principle quite different from that of a conventional bipolar transistor, and able to operate at an ultra high speed.
In general, the operating principle of a bipolar semiconductor device is well known. Namely, the operating speed of a conventional bipolar transistor is limited by the diffusion time of electrons running through the transistor, as later described in more detail with reference to FIG. 1.
A fairly new operating principle of so-called "resonant tunneling" is also known, and is disclosed in, for example, "Resonant Tunneling in Semiconductor Double Barriers", by L. L. Chang, L. Esaki, and R. Tsu, in Applied Physics Letters, Vol. 24, No. 12, 15 June, 1974.
A three-pole semiconductor device based on the principle of resonant tunneling is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 58-3277published on Jan. 10, 1983, Applicant: International Business Machines Corporation, Inventor: L. Esaki, claiming priority based on U.S. application Ser. No. 280,141 filed on Feb. 5, 1982. The device disclosed in this reference deals with majority carriers which are transmitted from the emitter to the collector using the phenomenon of resonant tunneling by controlling the base potential. The emitter region, the base region, and the collector region are all of the same conduction type, i.e., having n-type conductivity.